The Activity column in OneDrive My Files list view is used to help users stay up-to-date on the files that they are working on with others by surfacing relevant activity information. We will show file activity related to actions, such as, user comments, edits, share, and @mentions. When you create, complete or assign someone a task in office files the activity will also be logged.
How long is activity retained in the column?
The “Activity” column will show the last supported file activity for each file. The last activity description is retained in the Activity column until any new activity is performed on a particular file.
What type of events are expected to be shown in the column?
File Shared, File Comment, File Comment Reply, and @Mentions. In the future, we plan to add additional file activity types.
Does it work for external or guest users?
No, the Activity column will only show activity on files that are created or owned by a user.